Defining Computationally Minimal Art

(Or, taking the "8" out of "8-bit")

Written by Ville-Matias Heikkilä a.k.a. viznut/pwp,
released in the web on 2010-03-15. Also available in PDF format.

Introduction

"Low-tech" and "8-bit" are everywhere nowadays. Not only are the related
underground subcultures thriving, but "retrocomputing esthetics" seems to
pop up every now and then in mainstream contexts as well: obvious chip sounds
can be heard in many pop music songs, and there are many examples of "old
video game style" in TV commercials and music videos. And there are even
"pixel-styled" physical products, such as the pictured watch sold by the
Japanese company "&design". I'm not a grand follower of popular culture,
but it seems to me that the trend is increasing.

The most popular and widely accepted explanation for this phenomenon is
the "nostalgia theory", i.e. "People of the age group X are collectively
rediscovering artifacts from the era Y". But I'm convinced that there's more
to it -- something more profound that is gradually integrating "low-tech" or
"8-bit" into our mainstream cultural imagery.

Many people have became involved with low-tech esthetics via nostalgia,
but I think it is only the first phase. Many don't experience this phase at
all and jump directly to the "second phase", where pixellated graphics or
chip sounds are simply enjoyed the way they are, totally ignoring the
historical baggage. There is even an apparent freshness or novelty value for
some people. This happens with audiences that are "too young" (like the
users of Habbo Hotel) or otherwise more or less unaffected by the "oldskool
electronic culture" (like many listeners of pop music).

Since the role of specific historical eras and computer/gaming artifacts
is diminishing, I think it is important to provide a neutral conceptual
basis for "low-tech esthetics"; an independent and universal definition that
does not refer to the historical timeline or some specific cultural
technology. My primary goal in this article is to provide this definition
and label it as "Computationally Minimal Art". We will also be looking for
support for the universality of Computationally Minimal Art and finding
ur-examples that are even older than electricity.

A definition: Computationally Minimal Art

Once we strip "low-tech esthetics" from its historical and cultural
connections, we will be left with "pixellated shapes and bleepy sounds" that
share an essential defining element. This element stems from what is common
to the old computing/gaming hardware in general, and it is perfectly
possible to describe it in generic terms, without mentioning specific
platforms or historical eras.

The defining element is LOW COMPUTATIONAL COMPLEXITY, as expressed in all
aspects of the audiovisual system: the complexity of the platform (i.e. the
number of transistors or logic gates in the hardware), the complexity of the
software (i.e. the length in bits of the program code and static data), as
well as the time complexity (i.e. how many state changes the computational
tasks require). A more theoretical approach would eliminate the
differentiation of software and hardware and talk about description/program
length, memory complexity and time complexity.

There's little more that needs to be defined; all the important visible
and audible features of "low-tech" emerge from the various kinds of low
complexity. Let me elaborate with a couple of examples:

A low computing speed leads to a low number of processed and output bits
per time frame. In video output, this means low resolutions and limited
color schemes. In audio output, this means simple waveforms on a low
number of discrete channels.

A short program+data length, combined with a low processing speed, makes
it preferrable to have a small set of small predefined patterns
(characters, tiles, sprites) that are extensively reused.

A limited amount of temporary storage (emerging from the low hardware
complexity) also supports the former two examples via the small amount
of available video memory.

In general, the various types of low complexity make it possible for a
human being (with some expertise) to "see the individual bits with a
naked eye and even count them".

In order to complete the definition, we will still have to know what
"low" means. It may not be wise to go for an arbitrary threshold here ("less
than X transistors in logic, less than Y bits of storage and less than Z
cycles per second"), so I would like to define it as "the lower the better".
Of course, this does not mean that a piece of low-tech artwork would ideally
constitute of one flashing pixel and static square-wave noise, but that the
most essential elements of this artistic branch are those that persist the
longest when the complexity of the system approaches zero.

To summarize: "Computationally Minimal Art is a form of discrete art
governed by a low computational complexity in the domains of time,
description length and temporary storage. The most essential features of
Computationally Minimal Art are those that persist the longest when the
various levels of complexity approach zero."

How to deal with the low complexity?

Traditionally, of course, low complexity was the only way to go. The
technological and economical conditions of the 1970s and 1980s made the
microelectronic artist bump into certain "strict boundaries" very soon, so
the art needed to be built around these boundaries regardless of the
artist's actual esthetic ideals. Today, on the other hand, immense and
virtually non-limiting amounts of computing capacity are available for
practically everyone who desires it, so computational minimalism is nearly
always a conscious choice. There are, therefore, clear differences in how
the low complexity has been dealt with in different eras and
disciplines.

I'm now going to define two opposite approaches to low complexity in
computational art: optimalism (or "oldschool" attitude), which aims
at pushing the boundaries in order to fit in "as much beauty as possible",
and reductivism (or "newschool" attitude), which idealizes the low
complexity itself as a source of beauty.

Disclaimer: All the exaggeration and generalization is intentional! I'm
intending to point out differences between various extremities, not to
portray any existing "philosophies" accurately.

Optimalism

Optimalism is a battle of maximal goals against a minimal environment.
There are absolute predefined boundaries that provide hard upper limits for
the computational complexity, and these boundaries are then pushed by
fitting as much expressive power as possible between them. This approach is
the one traditionally applied to mature and static hardware platforms by the
video game industry and the demoscene, and it is characterized by the
appreciation of optimization in order to reach a high content density
regardless of the limitations.

A piece of
traditional European-style pixel graphics ("Frog, Landscape and a lot of
Clouds" by oys) exemplifies many aspects of optimalism. The resolution and
color constraints of a video mode (in this case, non-tweaked C-64
multicolor) provide the hard limits, and it is the responsibility of the
artist to fill up the space as wisely and densely as possible. Large
single-colored areas would look "unfinished", so they are avoided, and if it
is possible to fit in more detail or dithering somewhere, it should be done.
It is also avoidable to leave an available color unused -- an idea which
leads to the infamous "Dutch color scheme" when applied to high/truecolor
video modes.

When applied to chip music, the optimalist dogma tells, among all, to
fill in all the silent parts and avoid "simple beeps". Altering the values
of as many sound chip registers per frame as possible is thought to be
efficient use of the chip. This adds to the richness of the sound, which is
though to correlate with the quality of the music.

On platforms such as the Commodore 64, the demoscene and video game
industry seem to have been having relatively similar ideals. Once an
increased computing capacity becomes available, however, an important
difference between these cultures is revealed. Whenever the video game
industry gets more disk space or other computational resources, it will try
to use it up as aggressively as possible, without starting any optimization
efforts until the new boundaries have been reached. The demoscene, on the
other hand, values optimality and content density so much that it often
prefers to stick to old hardware or artificial boundaries in order to keep
the "art of optimality" alive. The screenshot is from the 4K demo "Artefacts" by Plush
(C-64).

Despite the cultural differences, however, the core esthetic ideal of
optimalism is always "bigger is better"; that an increased perceived content
complexity is a requirement for increased beauty. Depending on the
circumstances, more or less pushing of boundaries is required.

Reductivism

Reductivism is the diagonal opposite of optimalism. It is the
appreciation of minimalism within a maximal set of possibilities, embracing
the low complexity itself as an esthetic goal. The approach can be equated
with the artistic discipline of minimal art, but it should be remembered
that the idea is much older than that. Pythagoras, who lived around 2500
years ago, already appreciated the role of low complexity -- in the form of
mathematical beauty such as simple numerical ratios -- in music and art.

The reductivist approach does not lead to a similar pushing of boundaries
as optimalism, and in many cases, strict boundaries aren't even introduced.
Regardless, a kind of pushing is possible -- by exploring ever simpler
structures and their expressive power -- but most reductivists don't seem to
be interested in this aspect. It is usually enough that the output comes out
as "minimal enough" instead of being "as minimal as possible".

The visuals of the recent acclaimed Flash-based platformer game, VVVVVV,
are a good example of computational minimalism with a reductivist approach.
The author, Terry Cavanagh, has not only chosen a set of voluntary
"restrictions" (reminiscent of mature computer platforms) to guide the
visual style, but keeps to a reductivist attitude in many other aspects as
well. Just look at the "head-over-heels"-type main sprite -- it is something
that a child would be able to draw in a minute, and yet it is perfect in the
same iconic way as the Pac-Man character is. The style totally serves its
purpose: while it is charming in its simplicity and downright naivism, it
shouts out loud at the same time: "Stop looking at the graphics, have fun
with the actual game instead!"

Although reductivism may be regarded as a "newschool" approach, it is
possible to find some slightly earlier examples of it as well. The graphics
of the 1986 computer game Thrust, for example, has been drawn with simple
geometrical lines and arcs. The style is reminiscent of older vector-based
arcade games such as Asteroids and Gravitar, and it definitely serves a
technical purpose on such hardware. But on home computers with bitmapped
screens and sprites, the approach can only be an esthetical one.

Optimalism versus Reductivism

Optimalism and reductivism sometimes clash, and an example of this can be
found in the chip music community. After a long tradition of optimalism thru
the efforts of the video game industry and the demoscene, a new kind of
cultural branch was born. This branch, sometimes mockingly called
"cheaptoon", seems to get most of its kicks from the unrefined roughness of
the pure squarewave rather than the pushing of technological and musical
boundaries that has been characteristic of the "oldschool way". To an
optimalist, a reductivist work may feel lazy or unskilled, while an
optimalist work may feel like "too full" or "too refined" to a reductivist
mindset.

Still, when working within constraints, there is room for both
approaches. Quite often, an idea is good for both sides; a simple and short
algorithm, for example, may be appreciated by an optimalist because the
saved bytes leave room for something more, while a reductivist may regard
the technical concept as beautiful on its own right.

Comparison to Low-Complexity Art

While CMA is an attempt to formalize "low-tech computer art",
Schmidhuber's LCA comes from another direction, being connected to an
ages-old tradition that attempts to define beauty by mathematical
simplicity. The specific mathematical basis used in Schmidhuber's theory is
Kolmogorov complexity, which defines the complexity of a given string of
information (such as a picture) as the length of the shortest computer
program that outputs it. Kolmogorov's theory works on a high level of
generalization, so the choice of language does not matter as long as you
stick to it.

Schmidhuber sees, in "down-to-earth coder terms", that the human mind
contains a built-in "compressor" that attempts to represent sensory input in
a form as compact as possible. Whenever this compression process succeeds
well, the input is perceived as esthetically pleasing. It is a well-studied
fact that people generally perceive symmetry and regularity as more
beautiful than unsymmetry and irregularity, so this hypothesis of a "mental
compressor" cannot be dismissed as just an arbitrary crazy idea.

Low-Complexity Art tests this hypothesis by deliberately producing
graphical images that are as compressible as possible. One of the rules of
LCA is that an "informed viewer" should be able to perceive the algorithmic
simplicity quite easily (which also effectively limits the time complexity
of the algorithm, I suppose). Schmidhuber himself has devised a system based
on indexed circle segments for his pictures.

The above picture is from "Superego", a tiny pc demo I made in 1998. The
picture takes some tens of bytes and the renderer takes less than 100 bytes
of x86 code. Unfortunately, there is only one such picture in the demo,
although the 4K space could have easily contained tens of pictures. This is
because the picture design process was so tedious and counter-intuitive --
something that Schmidhuber has encountered with his own system as well.
Anyway, when I encountered Schmidhuber's LCA a couple of years after this
experiment, I immediately realized its relevance to size-restricted
demoscene productions -- even though LCA is clearly a reductivist approach
as opposed to the optimalism of the mainstream demoscene.

What Low-Complexity Art has in common with Computationally Minimal Art is
the concern about program+data length; a minimalized Kolmogorov complexity
has its place in both concepts. The relationship with other types of
complexity is different, however. While CMA is concerned about all the types
of complexity of the audiovisual system, LCA leaves time and memory
complexity out of the rigid mathematical theory and into the domain of a
"black box" that processes sensory input in the human brain. This makes LCA
much more theoretical and psychological than CMA, which is mostly concerned
about "how the actual bits move". In other words, LCA makes you look at
visualizations of mathematical beauty and ignore the visualization process,
while CMA assigns an utmost importance to the visualizer component as
well.

Psychological considerations

Now, an important question: why would anyone want to create Computationally
Minimal Art for purely esthetical reasons -- novelty and counter-esthetic
values aside? After all, those "very artificial bleeping sounds and flashing
pixels" are quite alien to an untrained human mind, aren't they? And even
many fans admit that a prolonged exposure to those may cause headache.

It is quite healthy-minded to assume that the perception mechanisms of the
human species, evolved during hundreds of millions of years, are "optimized"
for perceiving the natural world, a highly complex three-dimensional
environment with all kinds of complex lighting and shading conditions. The
extremely brief technological period has not yet managed to alter the
"built-in defaults" of the human mind anyhow. Studies show, for example,
that people all over the world prefer to be surrounded by wide-open
landscapes with some water and trees here and there -- a preference that was
fixed to our minds during our millions of years on the African savannah.

So, the untrained mind prefers a photorealistic, high-fidelity sensory
input, and that's it? No, it isn't that simple, as the natural surroundings
haven't evolved independently from the sensory mechanisms of their
inhabitants. Fruits and flowers prefer to be symmetric and vivid-colored
because animals prefer them that way, and animals prefer them that way
because it is beneficial for their survival to like those features, and so
on. The natural world is full of signalling which is a result of millions of
years of coevolutionary feedback loops, and this is also an important source
for our own sense of esthetics. (The fish in the picture, by the way, is a
Synchiropus splendidus, photographed by Luc
Viatour.)

I'm personally convinced that natural signalling has a profound
preference for low complexity. Symmetries, regularities and strong contrasts
are important because they are easy and effortless to detect, and the
implementation requires a relatively low amount of genetic coding on both
the "transmitter" and "receiver" sides. These are completely analogous to
the various types of computational complexity.

So, why does enjoying Computationally Minimal Art require "mental training"
in the first place? I think it is not because of the minimality itself but
because of certain pecularities that arise from the higher complexity of the
natural world. We can't see individual atoms or even cells, so we haven't
evolved a built-in sense for pixel patterns. Also, the sound generation
mechanisms in nature are mostly optimized to the constraints of pneumatics
rather than electricity, so we don't really hear squarewave arpeggios in the
woods (although some birds may come quite close).

But even though CMA requires some special adjustment from the human mind,
it is definitely not alone in this area. Our cultural surroundings are full
of completely unnatural signals that need similar adjustments. Our music
uses instruments that sound totally different from any animal, and
practically all musical genres (apart from the simplest lullabies, I think)
require an adjustment period. So, I don't think there's nothing particularly
"alien" in electronic CMA apart from the fact that it still hasn't yet
integrated in our mainstream culture.

CMA unplugged

The final topic we cover here is the extent where Computationally Minimal
Art, using our strict definition, can be found. As the definition is
independent from technology, it is possible to find ur-examples that predate
computers or even electricity.

In our search, we are ignoring the patterns found in the natural world
because none of them seem to be discrete enough -- that is, they fail to
have "human-countable bits". So, we'll limit ourselves to the artifacts
found in human culture.

Embroidery is a very old area of human culture that has its own tradition
of pixel patterns. I guess everyone familiar with electronic pixel art has
seen cross-stitch works that immediately bring pixel graphics in mind. The
similarities have been widely noted, and there have been quite many craft projects inspired by
old video games. But is this just a superficial resemblance or can we
count it as Computationally Minimal Art?

Cross-stitch patterns are discrete, as they use a limited set of colors
and a rigid grid form which dictates the positions of each of the X-shaped,
single-colored stitches. "Individual bits are perceivable" because each
pixel is easily visible and the colors of the "palette" are usually easy to
tell apart. The low number of pixels limits the maximum description length,
and one doesn't need to keep many different things in mind while working
either. Thus, cross-stitch qualifies all the parts of the definition of
Computationally Minimal Art.

What about the minimization of complexity? Yes, it is also there! Many
traditional patterns in textiles are actually algorithmic or at least highly
repetitive rather than "fully hand-pixelled". This is somewhat natural, as
the old patterns have traditionally been memorized, and the memorization is
much easier if mnemonic rules can be applied.

There are also some surprising similarities with electronic CMA. Many
techniques (like knitting and weaving) proceed one complete row of "pixels"
at a time (analogous to the raster scan of TV-like displays), and often, the
set of colors is changed between rows, which is corresponds very well to the
use of raster synchronization in oldschool computer graphics. There are even
peculiar technique-specific constraints in color usage, just like there are
similar constraints in many old video chips.

The picture above (source)
depicts a pillow knitted with the traditional Fair Isle technique. It is
apparent that there are two colors per "scanline", and these colors are
changed between specific lines (compare to rasterbars). The patterns are
based on sequential repetition, with the sequence changing on a per-scanline
basis.

Perhaps the most interesting embroidery patterns from the CMA point of view
are the oldest ones that remain popular. During centuries, the traditional
patterns of various cultures have reached a kind of multi-variable
optimality, minimizing the algorithmical and technical complexity while
maximizing the eye-pleasingness of the result. These patterns may very well
be worth studying by electronic CMA artists as well. Things like this are
also an object of study for the field of ethnomathematics, so that's another
word you may want to look up if you're interested.

What about the music department, then? Even though human beings have
written music down in discrete notation formats for a couple of millennia
already, the notes alone are not enough for us. CMA emphasizes the role of
the rendering, and the performance therefore needs to be discrete as well.
As it seems that every live performance has at least some non-discrete
variables, we will need to limit ourselves to automatic systems.

The earliest automatic music was mechanical, and arguably the simplest
conceivable automatic music system is the musical box. Although the musical
box isn't exactly discrete, as the barrel rotates continuously rather than
stepwise, I'm sure that the pins have been positioned with an engineer's
accuracy as guided by written music notation. So, it should be discrete
enough to satisfy our demands, and we may very well declare the musical box
as being the mechanical counterpart of chip music.

Conclusion

I hope these ideas can provide food for thought for people interested in
the various forms of "low-tech" electronic art as well as computational art
or "discrete art" in general. I particularly want people to realize the
universality of Computationally Minimal Art and how it works very well
outside of the rigid "historical" contexts it is often confined into.

I consciously skipped all the cultural commentary in the main text on my
quest for proving the universality of my idea, so perhaps it's time for that
part now.

In this world of endless growth and accumulation, I see Computationally
Minimal Art as standing for something more sustainable, tangible and crafty
than what the growth-oriented "mainstream cultural industry" provides. CMA
represents the kind of simplicity and timelessness that is totally immune to
the industrial trends of fidelity maximization and planned obsolescence. It
is something that can be brought to a perfection by an individual artist,
without hiring a thousand-headed army of specialists.

As we are in the middle of a growth phase, we can only guess what kind of
forms Computationally Minimal Art will get in the future, and what kind of
position it will eventually acquire in our cultural framework. We are living
interesting times indeed.